New research from the University of California published in Neurology has shown an association between quality of sleep and changes to cognitive function in midlife adults.
Over 500 people with an average age of 40, had their sleeping patterns tracked using a device worn on the wrist. They also completed thinking and memory tests to measure cognitive function at the beginning of the study and again just over a decade later.
The researchers found that those who had a higher level of disrupted sleep, were twice as likely to perform worse in memory and thinking tests than those who had the least disrupted sleep. They did not find a link between duration of sleep and cognitive performance.
Dr Susan Mitchell, Head of Policy at Alzheimer’s Research UK says:
“Many of us have experienced a bad night’s sleep and know that it can have an impact on our memory and thinking in the short term. But there are still gaps in our knowledge around whether sleep disturbances in midlife can increase our risk of developing dementia in the future.
“Previous studies suggest that how long we sleep each night can affect dementia risk. But less is known about disrupted sleeping patterns, so this study gives us interesting insight into how this may be affecting cognitive function.
“However, without a detailed picture of what’s going on in the brain, we don’t know whether the disrupted sleep patterns are causing the decline in cognition, or if a decline in cognition is causing the disturbances.
“Future studies looking at sleep disturbances in midlife, and whether they are linked to dementia risk in later life, are needed to get a clearer picture of cause and effect. Deeper insight into sleep and dementia could also be gained by studies looking at how levels of key Alzheimer’s disease proteins, such as amyloid or tau, are affected by sleep changes.
“While there is no sure-fire way to prevent dementia, there are things within our control that can reduce our risk, including keeping active, challenging our brains and keeping connected to the people around us. It’s never too early or late to start making positive changes.”